This invention relates to utility distribution networks, and more particularly, to a preterminated block system for use with buried distribution cable installations.
In recent years, utility distributors such as telephone companies have begun providing their services to residential customers in total out-of-sight plants. The concept of out-of-sight plants in the design of outside telephone distribution networks involves the use of field terminations between distribution cables and service wires which lead to individual customers. These terminations between distribution cables and service wires are located entirely underground and therefore must be carefully spliced and encapsulated to prevent damage. The need for quality splices and encapsulations between distribution cables and service wires as well as the desire to reduce costs has led to factory prefabrication of distribution networks, including the encapsulated connections, for later placement in the field. This allows for high quality testing prior to burying the connections.
Encapsulated terminations between distribution cables and service wires have conventionally been prefabricated by stringing out the distribution cable in a zig-zag or U arrangement, and splicing and encapsulating the service wires to the distribution cable at predetermined intervals along the length of the cable. Both the distribution cable and its service wires may then be wound up onto a reel and later transported to the job site and buried in a trench.
A more recent development is the reel-to-reel system which makes possible a more compact layout for prefabricating splices and encapsulations between distribution cables and service wires. In this system, the distribution cable is pulled off of one reel, passed through a work station where several service wires, usually, four, are spliced and encapsulated at predetermined intervals and then both the cable and service wires are reeled up onto a second reel ready for installation. The reel-to-reel system eliminates the large space requirements necessary in the zig-zag or U arrangements.
Preterminated service wires installed according to either of the above methods, however, have several disadvantages. Changes and rearrangements of the system are extremely difficult to make once the system is buried. If there are ultimately six customers to service instead of four or if additional wires for extra service or equipment is needed by a particular customer, the buried distribution cable must first be located and carefully dug up. Additional service wires must then be directly spliced into the distribution wire and encapsulated while working in the field. Furthermore, there are no aboveground test points provided along the cable to easily and quickly pinpoint any cable jacket or shield damage which may occur during or after installation of the distribution cable and its service wires.
A prefabricated distribution network in accordance with the present invention provides aboveground access points along the buried distribution cable to permit changes and rearrangements of the system as well as in-service testing capabilities not available from either of the above installations.